Transition metal catalysts for olefin polymerization

ABSTRACT

In one aspect, a chelating phosphine-phosphonic diamide (PPDA) ligand is described herein for constructing transition metal complexes operable for catalysis of olefin polymerization, including copolymerization of ethylene with polar monomer.

RELATED APPLICATION DATA

The present application is a continuation application of U.S. patentapplication Ser. No. 15/322,347 Dec. 27, 2016, which is a United StatesNational Phase of PCT/US2015/038104, filed Jun. 26, 2015, which claimspriority under 35 U.S.C. § 119(e) to U.S. Provisional Patent ApplicationSer. No. 62/018,263 filed Jun. 27, 2014, each of which is incorporatedherein by reference in its entirety.

STATEMENT OF GOVERNMENT RIGHTS

This invention was made with government support under Grant No.DMR-1420541 awarded by the National Science Foundation. The governmenthas certain rights in the invention.

FIELD

The present invention relates to transition metal complexes and, inparticular, to transition metal complexes operable for catalysis ofolefin polymerization.

BACKGROUND

Free radical olefin polymerization is well-known and commerciallyimportant. However, copolymerizations of ethylene with polar industrialmonomers, such as vinyl acetate and acrylic acid, are increasinglycomplex, requiring high temperature and exceedingly high pressures.Further, such processes intrinsically lack precise control over theresulting polymer architecture, polymer molecular weight andincorporation of polar monomer. In view of these deficiencies,coordination polymerization has been explored for potential controllablestrategies for the synthesis of polyolefins having variousfunctionalities derived from the incorporation of a polar monomer. Twodominant classes of transition metal catalysts have been developed todate for copolymerization of ethylene and industrial polar monomers. Thefirst class encompasses group 10 complexes coordinated by an α-diimineligand, commonly referred to Brookhart-type catalysts. The remainingclass employs neutral palladium complexes coordinated by a phosphinesulfonate (Drent-type). These two classes have persistent limitations.For Brookhart catalysts, complex stability is limited forpolymerizations conducted above room temperature. Even state-of-the-artBrookhart catalysts are persistent for only about 15 minutes at or above90° C. While Drent catalysts generally exhibit greater thermalstability, they typically produce low-molecular weight copolymers ofethylene and polar industrial monomers and/or turnover with poor rates.Therefore, new transition metal catalysts are required for theproduction of polar functionalized polyolefins.

SUMMARY

In one aspect, a chelating phosphine-phosphonic diamide (PPDA) ligand isdescribed herein for constructing transition metal complexes operablefor catalysis of olefin polymerization, including copolymerization ofethylene with polar monomer. A PPDA ligand described herein is ofFormula (I):

wherein A is selected from the group consisting of alkyl, alkenyl, aryland heteroaryl and wherein R¹, R², R³, R⁴, R⁵ and R⁶ are independentlyselected from the group consisting of alkyl, heteroalkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, alkyl-aryl and alkyl-heteroaryl,wherein R¹ and R² may optionally form a ring structure and anycombination of R³, R⁴, R⁵ and/or R⁶ may optionally form a ringstructure.

In another aspect, transition metal complexes are described hereinincorporating the PPDA ligand of Formula (I). Such transition metalcomplexes, in some embodiments, are suitable catalysts forcopolymerization of ethylene with polar monomer. In some embodiments, atransition metal complex described herein is of Formula (II):

wherein M is a transition metal, A is selected from the group consistingof alkyl, alkenyl, aryl and heteroaryl and wherein R¹, R², R³, R⁴, R⁵and R⁶ are independently selected from the group consisting of alkyl,heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyl-aryland alkyl-heteroaryl, wherein R¹ and R² may optionally form a ringstructure and any combination of R³, R⁴, R⁵ and/or R⁶ may optionallyform a ring structure and wherein R⁷ is selected from the groupconsisting of alkyl and aryl and R⁸ is selected from the groupconsisting of amine, heteroaryl, monophosphine, halo and sulfoxide andwherein X⁻ is a non-coordinating counter anion.

Further, in some embodiments, a transition metal complex is of Formula(III):

wherein M is a transition metal, A is selected from the group consistingof alkyl, alkenyl, aryl and heteroaryl, and wherein R¹, R², R³, R⁴, R⁵and R⁶ are independently selected from the group consisting of alkyl,heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyl-aryland alkyl-heteroaryl, wherein R¹ and R² may optionally form a ringstructure and any combination of R³, R⁴, R⁵ and/or R⁶ may optionallyform a ring structure and R⁷ and R⁸ are moieties of a chelating alkyl oraryl ligand, L, and wherein X⁻ is a non-coordinating counter anion. Insome embodiments, for example, R⁷ is an alkyl or aryl moiety and R⁸ is acarbonyl or oxide moiety of ligand, L.

In a further aspect, methods of olefin polymerization are describedherein. In some embodiments, a method of olefin polymerization comprisesproviding a reaction mixture of olefin monomer and transition metalcomplex of Formula (II) or Formula (III) and polymerizing the olefinmonomer in the presence of the transition metal complex to providepolyolefin. Polymerization can proceed by coordination-insertionpolymerization by which olefin monomer is added to the growing polymerchain through the transition metal complex of Formula (II) or Formula(III). In some embodiments, for example, suitable olefin monomer isethylene or propylene.

In another aspect, methods of olefin copolymerization are describedherein. A method of olefin copolymerization comprises providing areaction mixture of olefin monomer, polar monomer and transition metalcomplex of Formula (II) or Formula (III) and copolymerizing the olefinmonomer with the polar monomer in the presence of the transition metalcomplex. Copolymerization of the olefin and polar monomers can proceedby insertion or coordination polymerization through the transition metalcomplex. In some embodiments, suitable olefin monomer is ethylene orpropylene and polar monomer is selected from acrylic acid, alkyl acrylicacids, alkyl acrylates, acetates, vinyl ethers, acrylamide, vinyl ethersand/or acrylonitrile. Moreover, as described further herein, polarmonomer can be incorporated in-chain as opposed to incorporation atterminating end(s) of the copolymer.

Additionally, copolymer compositions are described herein. For example,a copolymer comprises olefin monomer and polar monomer, wherein greaterthan 50 percent of the polar monomer is positioned in-chain, and thecopolymer has molecular weight (Mw) of at least 5,000 Da. In someembodiments, the copolymer has molecular weight of at least 10,000 Da or20,000 Da. As described herein, suitable olefin monomer can be ethyleneor propylene and polar monomer is selected from acrylic acid, alkylacrylic acids, alkyl acrylates, acetates, vinyl ethers, acrylamideand/or acrylonitrile.

These and other embodiments are further described in the detaileddescription which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates chemical structures from which A of compoundsdescribed herein are selected according to some embodiments.

FIG. 2 illustrates aryl and heteroaryl chemical structures from which R¹and/or R² of compounds described herein are independently selectedaccording to some embodiments.

FIG. 3 illustrates alkyl, heteroalkyl and cycloalkyl chemical structuresfrom which R¹ and/or R² of compounds described herein are independentlyselected according to some embodiments.

FIG. 4 illustrates ring or cyclized structures formed by the combinationof R¹ and R² according to some embodiments described herein.

FIG. 5 illustrates alkyl, alkyl-aryl and heterocycloalkyl structuresfrom which R³, R⁴, R⁵ and/or R⁶ are independently selected according tosome embodiments.

FIG. 6 illustrates ring or cyclized structures formed by variouscombinations of R³, R⁴, R⁵ and/or R⁶ according to some embodiments.

FIG. 7 is a plot of productivity versus time for homopolymerization ofethylene by a transition metal complex of Formula (II) according to oneembodiment described herein.

DETAILED DESCRIPTION

Embodiments described herein can be understood more readily by referenceto the following detailed description and examples and their previousand following descriptions. Elements, apparatus and methods describedherein, however, are not limited to the specific embodiments presentedin the detailed description and examples. It should be recognized thatthese embodiments are merely illustrative of the principles of thepresent invention. Numerous modifications and adaptations will bereadily apparent to those of skill in the art without departing from thespirit and scope of the invention.

Definitions

The term “alkyl” as used herein, alone or in combination, refers to astraight or branched saturated hydrocarbon group optionally substitutedwith one or more substituents. For example, an alkyl can be C₁-C₃₀.

The term “alkenyl” as used herein, alone or in combination, refers to astraight or branched chain hydrocarbon group having at least onecarbon-carbon double bond and optionally substituted with one or moresubstituents.

The term “aryl” as used herein, alone or in combination, refers to anaromatic monocyclic or multicyclic ring system optionally substitutedwith one or more ring substituents. For example, an aromatic monocyclicor multicyclic ring system may be substituted with one or more of alkyl,alkenyl, alkoxy, heteroalkyl and/or heteroalkenyl.

The term “heteroaryl” as used herein, alone or in combination, refers toan aromatic monocyclic or multicyclic ring system in which one or moreof the ring atoms is an element other than carbon, such as nitrogen,oxygen and/or sulfur. The aromatic monocyclic or multicyclic ring systemmay further be substituted with one or more ring substituents, such asalkyl, alkenyl, alkoxy, heteroalkyl and/or heteroalkenyl.

The term “cycloalkyl” as used herein, alone or in combination, refers toa non-aromatic, saturated mono- or multicyclic ring system optionallysubstituted with one or more ring substituents.

The term “heterocycloalkyl” as used herein, alone or in combination,refers to a non-aromatic, saturated mono- or multicyclic ring system inwhich one or more of the atoms in the ring system is an element otherthan carbon, such as nitrogen, oxygen or sulfur, alone or incombination, and wherein the ring system is optionally substituted withone or more ring substituents.

The term “heteroalkyl” as used herein, alone or in combination, refersto an alkyl moiety as defined above, having one or more carbon atoms inthe chain, for example one, two or three carbon atoms, replaced with oneor more heteroatoms, which may be the same or different, where the pointof attachment to the remainder of the molecule is through a carbon atomof the heteroalkyl radical.

The term “alkoxy” as used herein, alone or in combination, refers to themoiety RO—, where R is alkyl or alkenyl defined above.

I. PPDA Ligand

In one aspect, a chelating phosphine-phosphonic diamide (PPDA) ligand isdescribed herein for constructing transition metal complexes operablefor catalysis of olefin polymerization, including copolymerization ofethylene with polar monomer. A PPDA ligand described herein is ofFormula (I):

wherein A is selected from the group consisting of alkyl, alkenyl, aryland heteroaryl and wherein R¹, R², R³, R⁴, R⁵ and R⁶ are independentlyselected from the group consisting of alkyl, heteroalkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, alkyl-aryl and alkyl-heteroaryl,wherein R¹ and R² may optionally form a ring structure and anycombination of R³, R⁴, R⁵ and/or R⁶ may optionally form a ringstructure.

Turning now to specific substituents of the PPDA ligand, A is selectedfrom alkyl, alkenyl, aryl and heteroaryl. FIG. 1 illustrates variousalkyl, alkenyl, aryl and heteroaryl structures from which A can beselected according to some embodiments described herein.

Moreover, R¹ and R² are independently selected from the group consistingof alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl,alkyl-aryl and alkyl-heteroaryl, wherein R¹ and R² may optionally form aring structure. In some embodiments, aryl or heteroaryl of R¹ and/or R²are substituted with one or more ring substituents. Such substituentscan include fluorinated alkyl, halide, alkoxy and heterocycloalkylstructures. In some embodiments, the substituents can be positionedortho and/or para on the ring. FIG. 2 illustrates various substitutedaryl and heteroaryl structures from which R¹ and/or R² can beindependently selected according to some embodiments described herein.Additionally, R¹ and/or R² can be independently selected from alkyl,heteroalkyl and cycloalkyl. FIG. 3 illustrates alkyl, heteroalkyl andcycloalkyl structures from which R¹ and/or R² can be independentlychosen according to some embodiments described herein. Further, R¹ andR² may form a ring structure. FIG. 4 illustrates ring structures formedby R¹ and R² according to some embodiments.

As described herein, R², R³, R⁴, R⁵ and R⁶ are independently selectedfrom the group consisting of alkyl, heteroalkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, alkyl-aryl and alkyl-heteroaryl.FIG. 5 illustrates alkyl, heterocycloalkyl and alkyl-aryl structuresfrom which R², R³, R⁴, R⁵ and/or R⁶ can be independently selectedaccording to some embodiments described herein. Additionally, anycombination of R³, R⁴, R⁵ and/or R⁶ may optionally form a ringstructure. FIG. 6 illustrates ring structures formed by variouscombinations of R³, R⁴, R⁵ and/or R⁶ according to some embodiments.

II. Transition Metal Complexes

In another aspect, transition metal complexes are described hereinincorporating the PPDA ligand of Formula (I). Such transition metalcomplexes, in some embodiments, are suitable catalysts forcopolymerization of ethylene with polar monomer. In some embodiments, atransition metal complex described herein is of Formula (II):

wherein M is a transition metal, A is selected from the group consistingof alkyl, alkenyl, aryl and heteroaryl and wherein R¹, R², R³, R⁴, R⁵and R⁶ are independently selected from the group consisting of alkyl,heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyl-aryland alkyl-heteroaryl, wherein R¹ and R² may optionally form a ringstructure and any combination of R³, R⁴, R⁵ and/or R⁶ may optionallyform a ring structure and wherein R⁷ is selected from the groupconsisting of alkyl and aryl and R⁸ is selected from the groupconsisting of amine, heteroaryl, monophosphine, halo and sulfoxide andwherein X⁻ is a non-coordinating counter anion.

Further, in some embodiments, a transition metal complex is of Formula(III):

wherein M is a transition metal, A is selected from the group consistingof alkyl, alkenyl, aryl and heteroaryl, and wherein R¹, R², R³, R⁴, R⁵and R⁶ are independently selected from the group consisting of alkyl,heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyl-aryland alkyl-heteroaryl, wherein R¹ and R² may optionally form a ringstructure and any combination of R³, R⁴, R⁵ and/or R⁶ may optionallyform a ring structure and R⁷ and R⁸ are moieties of a chelating alkyl oraryl ligand, L, and wherein X⁻ is a non-coordinating counter anion. Insome embodiments, for example, R⁷ is an alkyl or aryl moiety and R⁸ is acarbonyl or oxide moiety of ligand, L.

In some embodiments, A and R¹, R², R³, R⁴, R⁵ and R⁶ can be selectedfrom any of the structures illustrated in FIGS. 1-6 as described inSection I above. Further, X⁻ is a non-coordinating counter anion, whichpreferably exhibits suitable organic solvent solubility. Suitablenon-coordinating counter anions can include borates and aluminates. Insome embodiments, for example, X⁻ is selected from the group consistingof [B[3,5-(CF₃)₂C₆H₃]₄]⁻ also designated as [BAr^(F) ₄]⁻, [B(C₆F₅)₄]⁻,Al[OC(CF₃)₃]₄ ⁻, SbF₆ and PF₆.

M can be any transition metal not inconsistent with the objectives ofthe present invention. For example, in some embodiments, M is selectedfrom Group 10 of the Periodic Table consisting of nickel, palladium andplatinum. However, M can also be selected from earlier group(s) oftransition metal elements. Examples 2 and 3 hereinbelow provide severaltransition metal complexes of Formulas (II) and (III) respectivelywherein palladium is the transition metal.

III. Methods of Polymerization

In a further aspect, methods of olefin polymerization are describedherein. In some embodiments, a method of olefin polymerization comprisesproviding a reaction mixture of olefin monomer and transition metalcomplex of Formula (II) or Formula (III) and polymerizing the olefinmonomer in the presence of the transition metal complex to providepolyolefin. Polymerization can proceed by coordination-insertionpolymerization by which olefin monomer is added to the growing polymerchain through the transition metal complex of Formula (II) or Formula(III). In some embodiments, for example, suitable olefin monomer isethylene or propylene. Moreover, in some embodiments, polymerization ofolefin monomer can proceed in the presence of various contaminants thatprior transition metal catalyst cannot tolerate. In some embodiments,polymerization of olefin monomer by transition metal complexes ofFormulas (II) and/or (III) can proceed in the presence of diethyl ether,ethylacetate and/or other similar species found in dirty ethylenestreams.

In another aspect, methods of olefin copolymerization are describedherein. A method of olefin copolymerization comprises providing areaction mixture of olefin monomer, polar monomer and transition metalcomplex of Formula (II) or Formula (III) and copolymerizing the olefinmonomer with the polar monomer in the presence of the transition metalcomplex. Copolymerization of the olefin and polar monomers can proceedby insertion or coordination polymerization through the transition metalcomplex. In some embodiments, suitable olefin monomer is ethylene orpropylene and polar monomer is selected from acrylic acid, alkyl acrylicacids, alkyl acrylates, alkenyl acetates, acrylamide, vinyl ethersand/or acrylonitrile. Moreover, as described further below withreference to Table II, polar monomer can be incorporated in-chain asopposed to incorporation at terminating end(s) of the copolymer.

Importantly, transition metal complexes of Formula (II) and/or Formula(III) can exhibit marked thermal stability often persisting for at least24 hours at 100° C. during polymerization of ethylene. Such thermalstability allows transition metal complexes described herein to providehomopolymers and copolymers of molecular weight in excess of 10,000 Da,a threshold generally allowing for desirable physical properties. Insome embodiments, homopolymers and copolymers produced according tomethods described herein have molecular weight of 10,000-250,000. FIG.7, for example, is a plot of productivity versus time forhomopolymerization of ethylene by a transition metal complex of Formula(II) according to one embodiment described herein. The transition metalcomplex is 18 described in the following Examples.

Additionally, copolymer compositions are described herein. For example,a copolymer comprises olefin monomer and polar monomer, wherein greaterthan 50 percent of the polar monomer is positioned in-chain, and thecopolymer has molecular weight (M_(w)) of at least 5,000 Da or at least10,000 Da. As used herein, “in-chain” refers to distribution of thepolar monomer along interior regions or positions of the polymericchain, as opposed to incorporation of polar monomer at the ends of thepolymeric chain. The ability to distribute polar monomer in-chainprovides unique properties to the resultant copolymer. For example,in-chain distribution of polar monomer can provide the copolymerenhanced gas barrier properties. In some embodiments, such copolymer canexhibit enhanced barrier properties to oxygen and/or other degradativegases, thereby enabling use of the copolymer in various gas barrierapplications such as food packaging, barrier films for electronics andsubstrates for dye-sensitized photovoltaics and/or thin filmtransistors.

Moreover, in-chain distribution of polar monomer can enhance adhesioncharacteristics of the copolymer relative to polyolefins, such as LDPEand HDPE. Enhanced adhesion characteristics expand compatibility of thecopolymer with a variety of materials including dyes and/or other polarpolymeric species and coatings. Therefore, copolymer described hereincan serve as a bulk structural material for various laminate and/orsurface coated architectures without the requirement of special surfacepretreatments, such as exposure to peroxide or plasma, to render thesurface hydrophilic. In-chain polar monomer can also serve as locationsfor anchoring various species to the copolymer. For example, variousbiological molecules including amino acids and peptides may be attachedvia exposed functional groups of the copolymer leading to biologicalmolecule immobilization. In additional aspect, in-chain polar monomercan permit copolymer described herein to serve as a compatibilizingagent for polymer blends. In some embodiments, the copolymer can inhibitphase separation in a mixture of two or more immiscible polymericspecies.

In some embodiments, copolymer having in-chain polar monomer hasmolecular weight selected from Table I:

TABLE I Copolymer Molecular Weight (M_(w)) Da ≥20,000 ≥30,000 ≥40,000≥50,000 ≥100,000 10,000-200,000Additionally, percentage of polar monomer of the copolymer incorporatedin-chain can be selected from Table II. As provided in Table II, polarmonomer, in some embodiments, is exclusively incorporated in-chain.

TABLE II Polar Monomer In-chain (%) ≥60 ≥70 ≥80 ≥90 ≥95 ≥99 100 50-100Further, mol. % of polar monomer incorporated into the copolymer can beselected from Table III.

TABLE III mol. % Polar Monomer Incorporated into Copolymer 0.5-15  3-153-10 3-8  5-15 5-10 10-15 As described herein, suitable olefin monomer can be ethylene and/orpropylene and polar monomer is selected from acrylic acid, alkyl acrylicacids, alkyl acrylates, acetates, acrylamide, vinyl ethers and/oracrylonitrile.

These and other embodiments are further illustrated by the followingnon-limiting examples.

Example 1—Synthesis of PPDA Ligands

yield entry compound R¹ R² (%)  1  1 i-C₃H₇ CH₃  —^(a)  2  22-(CH₃O)C₆H₄ CH₃ 52  3  3 i-C₃H₇ i-C₃H₇ 69  4  4 i-C₅H₁₁ i-C₃H₇ 74  5  5C₆H₅ i-C₃H₇ 92  6  6 2-FC₆H₄ i-C₃H₇ 15  7  7 2,6-F₂C₆H₃ i-C₃H₇ 35  8  82-(CH₃O)C₆H₄ i-C₃H₇ 75  9  9 2-furyl i-C₃H₇ 43 10 10 2-(CF₃O)C₆H₄ i-C₃H₇24 ^(a)Used directly without isolation.

Representative Synthesis of a PPDA Ligand: N,N,N′,N′-tetraisopropyl2-[bis(2-methoxyphenyl)phosphino]phenylphosphonic diamide (8)

To a solution of N,N,N′,N′-tetraisopropyl phenylphosphonic diamide (0.65g, 2.0 mmol) in THF (30 mL) was added tert-butyllithium (1.4 mL, 2.4mmol, 1.7 M in pentane) at −78° C. The mixture was then warmed to −30°C. and stirred for 3 h. A THF solution ofbis(2-methoxyphenyl)chlorophosphine (0.84 g, 3.0 mmol) was added to thereaction mixture and then stirred for 30 min after slowly warming toroom temperature. Evaporation of solvent and purification of the residueby column chromatography (ethyl acetate/hexane) gave 0.85 g (75%) of 8as a white solid. ¹H NMR (500 MHz, CDCl₃) δ 7.85 (ddd, J=11, 7, 4 Hz,1H), 7.32 (td, J=7, 3 Hz, 1H), 7.26 (t, J=11 Hz, 3H), 7.07 (dt, J=7, 3Hz, 1H), 6.85 (dd, J=8, 4 Hz, 2H), 6.78 (t, J=7 Hz, 2H), 6.60 (s, 2H),3.78-3.65 (m, 10H), 1.32 (d, J=7 Hz, 12H), 1.23 (d, J=7 Hz, 12H). ³¹PNMR (121 MHz, CDCl₃) δ 29.5, −25.8. ¹³C NMR (125 MHz, CDCl₃) δ 160.9,143.7, 140.2, 135.5, 134.2, 133.2, 130.1, 129.0, 128.1, 126.5, 120.5,110.0, 55.2, 46.6, 24.2. HRMS (ESI) m/z Calc'd for C₃₂H₄₆N₂O₃P₂+H (M+H)569.3062, Found 569.3094.

Compound 2 was prepared in an analogous way as for 8; 0.65 g (52%) of 2was obtained as a white solid. ¹H NMR (500 MHz, CDCl₃) δ 8.24 (ddd,J=11, 8, 3 Hz, 1H), 7.44 (td, J=7, 3 Hz, 1H), 7.37-7.27 (m, 3H), 7.06(d, J=7 Hz, 1H), 6.88 (d, J=8 Hz, 2H), 6.83 (td, J=7, 3 Hz, 2H), 6.56(s, 2H), 3.68 (s, 6H), 2.70-2.34 (m, 12H). ³¹P NMR (203 MHz, CDCl₃) δ30.9, −27.7. ¹³C NMR (126 MHz, CDCl₃) δ 160.9, 141.3, 137.4, 136.0,135.1, 134.1, 131.2, 129.9, 128.4, 125.6, 121.0, 109.9, 55.4, 36.8. HRMS(ESI) m/z Calc'd for C₂₄H₃₀N₂O₃P₂+H (M+H) 457.1810, Found 457.1802.

Example 2—Synthesis of cationic (PPDA)(methyl)(lutidine)palladiumcomplexes

yield entry compound R¹ R² (%)  1 11 i-C₃H₇ CH₃ 89  2 12 2-(CH₃O)C₆H₄CH₃ 84  3 13 i-C₃H₇ i-C₃H₇ 86  4 14 i-C₅H₁₁ i-C₃H₇ 90  5 15 C₆H₅ i-C₃H₇85  6 16 2-FC₆H₄ i-C₃H₇ 81  7 17 2,6-F₂C₆H₃ i-C₃H₇ 92  8 18 2-(CH₃O)C₆H₄i-C₃H₇ 65  9 19 2-furyl i-C₃H₇ 92 10 20 2-(CF₃O)C₆H₄ i-C₃H₇ 88

Representative Synthesis of a (PPDA)Palladium Catalyst:[(8-κ-P,κ-O)(methyl)(2,6-lutidine)palladium]{tetrakis[3,5-bis(trifluoromethyl)phenyl]borate} (18)

(1,5-cyclooctadiene)(chloro)(methyl)palladium (178 mg, 0.67 mmol) and 8(381 mg, 0.67 mol) were weighed into a small vial. The mixture wasdissolved in dichloromethane (5 mL) at room temperature, and thesolution was stirred for 10 min. The total volume was reduced to ca. 2mL under reduced pressure and then diluted with toluene (10 mL). Afterstanding overnight, the mother liquor was decanted, the solids werewashed with toluene and pentane then dried under vacuum to afford 409 mgof (8-κ-P,κ-O)(chloro)(methyl)palladium.

(8-κ-P,κ-O)(chloro)(methyl)palladium (80 mg, 0.11 mmol) and 2,6-lutidine(13 mg, 0.12 mmol) were weighed into a small vial and dissolved indichloromethane (5 mL). The solution was then added to a flaskcontaining sodium tetralkis[3,5-bis(trifluoromethyl)phenyl]borate (98mg, 0.11 mmol) cooled to −78° C. The mixture was slowly warmed to rtwith vigorous stirring. Stirring was continued for an additional 30 minat rt. The solids were removed by filtration through Celite, thefiltrate was concentrated to ca. 2 mL, and then diluted with toluene (10mL). After standing overnight, the precipitate was filtered and washedwith pentane then dried under vacuum to afford 119 mg (65%) of 18 as apale yellow solid. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.68 (dd, J=16, 8 Hz, 1H),7.90 (ddd, J=15, 8, 5 Hz, 1H), 7.82 (s, 8H), 7.71 (dd, J=15, 10 Hz, 2H),7.67-7.60 (m, 6H), 7.52 (t, J=8 Hz, 1H), 7.35-7.22 (m, 4H), 7.12 (dd,J=8, 6 Hz, 1H), 7.06-6.97 (m, 2H), 6.77 (dd, J=12, 8 Hz, 1H), 3.78 (s,3H), 3.70-3.61 (m, 2H), 3.53 (s, 3H), 3.49-3.41 (m, 2H), 3.31 (s, 3H),3.18 (s, 3H), 1.16 (d, J=7 Hz, 6H), 1.05 (d, J=7 Hz, 6H), 1.02 (d, J=7Hz, 6H), 0.93 (d, J=7 Hz, 6H), 0.00 (d, J=3 Hz, 3H). ³¹P NMR (121 MHz,CD₂Cl₂) δ 30.2, 24.9. ¹⁹F NMR (300 MHz, CD₂Cl₂) 6-62.9. ¹³C NMR (125MHz, CD₂Cl₂) δ 161.7, 159.2, 158.6, 140.6, 138.5, 137.8, 136.8, 136.6,135.0, 134.8, 134.0, 133.6, 133.0, 129.9, 129.3, 129.2, 128.9, 128.8,125.2, 124.6, 122.7, 121.3, 120.6, 117.4, 116.0, 115.3, 111.7, 111.1,54.9, 47.5, 47.3, 26.4, 24.2, 23.6, 22.7, 22.1, −2.8.

Example 3—Synthesis of Cationic (PPDA)[2-acetanilido-κ-C,κ-O]palladiumComplexes

yield Compound R¹ R² (%) 21 i-C₃H₇ CH₃ 86 22 2-(CH₃O)C₆H₄ CH₃ 95 23i-C₃H₇ i-C₃H₇ 79 24 2-(CH₃O)C₆H₄ i-C₃H₇ 88

Representative Synthesis of a (PPDA)Palladium Catalyst:{(8-κ-P,κ-O){2-[(acetyl-κ-O)amino]phenyl-κC}palladium}{tetrakis[3,5-bis(trifluoromethyl)phenyl]borate}(24)

Bis[μ-(chloro)]bis[2-[(acetyl-κ-O)amino]phenyl-κ-C]dipalladium (111 mg,0.40 mmol) and 8 (228 mg, 0.40 mmol) were weighed into a vial and CH₂Cl₂(5 mL) was then added. The suspension was stirred at room temperaturefor 3 h. The solution was filtered through Celite, the filtrate wasconcentrated to ca. 2 mL, and the solution was diluted with toluene (10mL). After standing overnight, the precipitate was filtered, washed withpentane, and then dried under vacuum to afford 241 mg of(8-κ-P,κ-O)[2-(N-acetylamino)phenyl](chloro)palladium as a yellow solid.

(8-κ-P,κ-O)[2-(N-acetylamino)phenyl](chloro)palladium (137 mg, 0.16mmol) was dissolved in CH₂Cl₂ (5 mL) and the solution was added to aflask containing AgSbF₆ (56 mg, 0.16 mmol) cooled to −78° C. The mixturewas slowly warmed to room temperature over 30 min. The solids wereremoved by filtration through Celite, the filtrate was concentrated toca. 2 mL, and the solution was diluted with toluene (10 mL). Afterstanding overnight, the precipitate was filtered, washed with pentane,and dried under vacuum to afford 135 mg of{(8-κ-P,κ-O)[2-[(acetyl-κ-O)amino]phenyl-κ-C]palladium}{SbF₆} as ayellow solid.

{(8-κ-P,κ-O)[2-[(acetyl-κ-O)amino]phenyl-κ-C]palladium}{SbF₆} (74 mg,0.069 mmol) and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate(62 mg, 0.069 mmol) were weighed into a vial. CH₂Cl₂ (5 mL) was thenadded, and the mixture was stirred for 15 min. The solids were removedby filtration through Celite, the filtrate was concentrated to ca. 2 mL,and then diluted with pentane (10 mL). After standing overnight, theprecipitate was filtered, washed with pentane, and dried under vacuum toafford 102 mg (88%) of 24 as a yellow solid. 1H NMR (500 MHz, CD₂Cl₂) δ8.77 (s, 1H), 7.86 (s, 1H), 7.71-7.62 (m, 1H), 7.58 (s, 8H), 7.48 (t,J=8 Hz, 1H), 7.42 (s, 4H), 7.40-7.30 (m, 2H), 7.29-7.17 (m, 2H),7.12-7.05 (m, 1H), 6.82-6.72 (m, 2H), 6.67 (d, J=8 Hz, 1H), 6.55 (t, J=8Hz, 1H), 6.48-6.40 (m, 1H), 6.38 (dd, J=8, 2 Hz, 1H), 6.26 (t, J=8 Hz,1H), 5.99 (t, J=8 Hz, 1H), 3.64-3.49 (m, 2H), 3.47-3.21 (m, 5H), 3.17(s, 3H), 2.21 (s, 3H), 1.25 (d, J=7 Hz, 6H), 1.01 (d, J=7 Hz, 6H), 0.98(d, J=7 Hz, 6H), 0.73 (d, J=7 Hz, 6H). ³¹P NMR (203 MHz, CD₂Cl₂) δ 30.9,28.3. ¹³C NMR (125 MHz, CD₂Cl₂) δ 169.4, 161.8, 141.1, 140.0, 137.2,136.7, 136.6, 136.0, 159.6, 134.7, 133.8, 133.5, 133.1, 132.6, 132.2,130.5, 130.4, 129.7, 129.6, 128.8, 127.5, 124.63, 124.58, 123.8, 121.8,120.7, 117.5, 115.0, 112.1, 111.4, 54.8, 47.8, 47.5, 23.7, 22.5, 22.1,22.0.

Example 4—Polymerization of Ethylene by a (PPDA)Pd Complex

catalyst C₂H₄ time yield activity M_(w) ^(a) Ð Entry (μM) (bar) (min)(g) [kg (mol Pd)⁻¹ h⁻¹] (Da) (M_(w)/M_(n))^(a) Me br^(b)  1 11 (25) 3060 7.14  2,900  5,200 1.8 0.5   2^(c) 12 (50) 30 30 1.53  4,600  37,0005.1 21  3   12 (12.5) 30 15 0.95  3,100 160,000 2.0 n.d.^(d)  4 12 (25)30 15 3.60  5,800 120,000 1.6 1.4  5 12 (25) 15 30 3.56  2,800 130,0001.6 2.9  6 12 (25) 7 30 2.48  2,000 100,000 1.5 2.7  7 12 (25) 3.5 301.19   950  21,000 2.5 7.0  8 13 (25) 30 15 1.08  1,700  39,000 1.6 2.5 9 14 (25) 23 30 2.60  1,000  81,000 1.4 16 10 15 (25) 30 30 trace — — —— 11 16 (25) 30 60 4.80  1,900  88,000 1.5 n.d.^(d) 12 17 (25) 30 156.30 10,000  80,000 1.8 3.0   13^(c) 18 (50) 30 30 1.74  5,700  26,0005.7 n.d.^(d) 14 18 (25) 30 15 1.35  2,200 240,000 1.4 13 15 18 (25) 3.5120  1.35   270  16,000 1.6 21 16 19 (25) 30 60 1.45   580  1,400 1.7n.d.^(d) 17 20 (25) 30 30 trace — — — — 18 24 (25) 30 30 0.19   160160,000 1.3 n.d.^(d) 19   30 (12.5) 30 15 0.52  1,700 140,000 1.3 4 20  31 (12.5) 30 15 2.12  6,800 120,000 1.4 7 ^(a)Absolute molecularweight and polydispersity determined by GPC analysis with tripledetection. ^(b)Methyl branches per 1000 carbons as determined by ¹H orquantitative ¹³C NMR spectroscopy. . ^(c)Reaction conducted in a 7-wellautoclave; 10 mL total volume. ^(d)Not determined.

Example 5—Copolymerization of Ethylene and Polar Monomer Catalyzed by a(PPDA)Pd Complex

catalyst R time yield activity M_(w) ^(a) Ð χ^(c) Entry (mM) (M) (h) (g)[kg (mol Pd)⁻¹ h⁻¹] (Da) (M_(w)/M_(n)) Me br^(b) (%) 1 12 (0.67)  CO₂H(1.5) 15 0.66 4.4 31,000 2.9 1.2 2.7  2^(d) 12 (0.67) CO₂Me (2.2) 120.27 2.2 21,000 1.4 7.4 2.0 3 12 (0.67) CO₂Me (2.2) 15 1.48 9.9 74,0001.6 2.1 0.7 4 17 (0.67) CO₂Me (2.2)  9 0.83 9.2  9,100 3.5 n.d.^(e)n.d.^(e) 5 18 (0.67) CO₂Me (2.2) 13 0.32 2.4 29,000 1.4 4.8 1.3 6 23(0.69) CH₂OAc (1.6)  15 0.97 6.2 23,000 2.1 2.5 1.0 7 12 (0.67) CH₂OAc(1.6)  12 0.79 6.6  4,900 4.5 n.d.^(e) 1.2 8 17 (0.67) CO₂Me (2.2)  90.83 9.2  9,000 3.5 4.7 1.8  9^(f) 30 (0.70) CO₂Me (2.2) 12 1.03 8.319,000 1.5 n.d.^(e) 3.7 10^(f)   31 (0.86) CO₂Me (2.2) 12 4.11 26  34,000 1.8 n.d.^(e) 8.6 ^(a)Absolute molecular weight and polydispersitydetermined by GPC analysis with triple detection. ^(b)Methyl branchesper 1000 carbons as determined by ¹H NMR spectroscopy. ^(c)Mole fractionof polar monomer incorporated into the product as determined by ¹H NMRspectroscopy. ^(d)95° C.. ^(e)Not determined. ^(f)100° C.

Representative Procedure for Polymerizations: Reaction of Ethylene and18.

A 450 mL stainless steel autoclave was dried in an oven at 120° C., andthen allowed to cool inside a dry box. After cooling, 4.2 mg (0.0025mmol) of 18 was added and diluted with toluene (100 mL). The autoclavewas sealed, equilibrated to 100° C., and then charged with ethylene (30bar). After 15 min, the autoclave was vented and the reaction wasquenched by addition of MeOH. The solids were filtered, washed withMeOH, and dried under vacuum at 70° C. overnight. The molecular weightand polydispersity were determined by size exclusion chromatography. Theextent of branching in the polymer backbone was determined by ¹H NMRspectroscopy at 120° C. in CDCl₂CDCl₂.

Example 6—Synthesis of Cationic (PPDA-)Ni Complexes

H(OEt₂)₂BAr₄ ^(F) and NiMe₂py₂ were prepared according to literatureprocedure of Brookhart et al., Organometallics, 2003 11 (11) 3920 andCampora et al., J. Organomet. Chem., 2003, 683, 220, respectively.

(8)NiBr₂ was first formed by stirring the PPDA ligand (8) of Example 2with Ni(II)bromide ethylene glycol dimethyl ether complex, followed byevaporation of volatiles. 2-Mesitylmagnesium bromide solution (1M inTHF, 0.23 mmol) was added to a THF solution of (8)NiBr₂ (0.18 g, 0.23mmol) at −78° C. The mixture was then slowly warmed to room temperatureand stirred for 1 h. The solvent was removed under vacuum. The residuewas recrystallized from tolulene to give 25 as an orange solid (0.18 g,93% yield).

¹H NMR (500 MHz, CD₂Cl₂) δ 7.83-7.01 (m, 10H), 6.54 (br, 2H), 5.80 (br,2H), 3.75 (br, 4H), 3.40 (br, 6H), 2.93 (br, 6H), 2.33 (br, 3H), 1.18(br, 24H).

¹³C NMR (125 MHz, CD₂Cl₂) δ 160.44, 141.42, 136.34 (d, J=12.8 Hz),135.38, 135.16 (d, J=9.9 Hz), 134.06 (d, J=15.2 Hz), 132.43 (d, J=8.5Hz), 131.81 (dd, J=36.1, 5.1 Hz), 129.96, 129.22, 128.75 (d, J⁼5.7 Hz),128.41, 128.31, 127.03, 125.49, 123.97, 120.41, 110.11, 47.70 (d, J=6.1Hz), 27.15, 24.36, 23.86, 19.64.

³¹P NMR (203 MHz, CD₂Cl₂) δ 29.7 (d, J=11.2 Hz), 11.65 (d, J=11.6 Hz).

NaBAr^(F) ₄ (71 mg, 0.080 mmol) in CH₂Cl₂ was added to a CH₂Cl₂ solutionof 25 (66 mg, 0.080 mmol) and DMSO (24 mg, 0.32 mmol). After stirred atroom temperature for 1 h, the solvent was removed and the residue wasrecrystallized from toluene and CH₂Cl₂ to give 26 as an a orange solid(80 mg, 59% yield).

¹H NMR (500 MHz, CD₂Cl₂) δ 7.77 (br, 11H), 7.61 (br, 4H), 7.55-7.40 (m,5H), 7.05 (br, 2H), 6.62 (br, 2H), 6.01 (br, 2H), 3.87-3.65 (m, 4H),3.44 (br, 6H), 3.16-2.77 (m, 6H), 2.41-2.22 (m, 6H), 1.95 (br, 3H), 1.19(br, 24H).

¹³C NMR (125 MHz, CD₂Cl₂) δ 162.26 (q, J=49.8 Hz), 160.60, 143.12,136.32 (dd, J=12.4, 2.4 Hz), 135.31, 135.06 (d, J=4.9 Hz), 134.18 (d,J=10.5 Hz), 134.04 (d, J=4.5 Hz), 133.72 (d, J=9.4 Hz), 133.47, 132.80(t, J=9.1 Hz), 129.87 (dd, J=7.1, 2.8 Hz), 129.66 (d, J=2.3 Hz), 129.38(qq, J=31.5, 2.9 Hz), 125.76, 125.11 (q, J=272.3 Hz), 120.81 (d, J=11.7Hz), 118.00 (p, J=4.3 Hz), 116.52, 116.08, 110.89, 54.71, 48.14 (d,J=6.0 Hz), 38.54, 26.40, 24.19 (dd, J=44.2, 3.3 Hz), 20.05.

³¹P NMR (203 MHz, CD₂Cl₂) δ 32.31 (d, J=10.9 Hz), 16.71 (d, J=11.2 Hz).HRMS (ESI) m/z calc'd for C41H57N2NiO3P2 (M⁺-DMSO) 745.3198, found745.3199.

H(OEt₂)₂BAr₄ ^(F) (0.25 g, 0.25 mmol) and PPDA ligand (0.11 g, 0.25mmol) were dissolved in toluene (3 mL). The solution was added into asolution of NiMe₂py₂ (0.068 g, 0.28 mmol) dissolved in toluene (3 mL).After stirring for 4 hours, the dark red solution was filtered to removeblack Ni⁰. The solvent was reduced and layered with pentane. Theresulting dark brown oil was triturated three times with Et₂O (5 mL) anddried to yield 27 as a light brown solid (0.27 g, 74%).

¹H NMR (500 MHz, CD₂Cl₂) δ_(H) 8.74 (br, 2H), 7.79-8.0 (br, 6H), 7.72(s, 8H), 7.56 (s, 4H), 7.31-7.51 (br, 5H), 7.05 (br, 4H), 3.80 (s, 6H),2.27 (d, J=10 Hz, 12H), −0.95 (d, J=10 Hz, 3H).

¹³C NMR (125 MHz, CD₂Cl₂) δ_(C) 161.70 (q, J=50 Hz), 160.65, 149.83,147.20, 137.92, 135.98, 135.17 (d, J=12 Hz), 134.72, 133.557, 132.69,131.73 (d, J=50 Hz), 130.17 (d, J=11 Hz), 128.83 (d, J=32 Hz), 126.91,125.64, 124.76, 123.47, 121.00 (d, J=9 Hz), 117.44, 111.42, 55.40,35.76, −10.60 (d, J=10 Hz).

³¹P NMR (203 MHz, C₆D₆) δ_(P) 31.1 (d, J=14 Hz), 13.5 (br). HRMS (ESI)m/z calc'd for C25H33N2NiO3P2 (M-pyridine) 529.1909.

Prepared using a similar procedure as for 27. Complex 28 was isolated asan orange solid (71 mg, 61%).

¹H NMR (300 MHz, CD₂Cl₂) δ_(H) 8.44 (s, 8H), 8.13 (br, 1H), 7.76 (m,4H), 7.73 (m, 2H), 7.42 (m, 1H), 6.85 (m, 2H), 6.78 (t, J=6.0 Hz, 1H),6.60 (t, J=6.0, 2H), 3.41 (br, 4H), 3.18 (s, 6H), 0.74 (br, 24H), −0.89(d, J=6.0 Hz, 3H).

¹³C NMR (125 MHz, C₆D₆) δ_(C) 150.16, 138.01, 135.90 (d, J=13 Hz),134.75, 133.57, 133.20, 132.77, 130.51, 129.38, 125.92, 124.92, 123.76,121.08, 118.52, 117.57 (d, J=35 Hz), 116.63, 116.00, 111.61, 47.33,29.69, 24.18, 23.38, 22.34, −10.04 (d, J=36 Hz).

³¹P NMR (122 MHz, C₆D₆) δ_(P) 30.0 (d, J=12 Hz), 14.2 (br). HRMS (ESI)m/z calc'd for C33H49N2NiO3P2 (M-pyridine) 641.2572.

Prepared using a similar procedure as for 27. Complex 29 was isolated asa yellow solid (55 mg, 58%). ¹H NMR (300 MHz, C₆D₆) δ_(H) 8.41 (br, 8H),7.67 (br, 4H), 7.42 (m, 1H), 6.89 (m, 2H), 6.81 (m, 2H), 6.71 (m, 3H),6.48 (m, 7H), 3.19 (septet, J=6 Hz, 4H), 0.84 (d, J=6 Hz, 12H), 0.67 (d,J=6 Hz, 12H), −0.83 (d, J=9 Hz, 3H).

¹³C NMR (125 MHz, CD₂Cl₂) δ_(c) 164.33, 161.71 (q, J=50 Hz), 150.31,138.45, 135.11, 134.75, 133.31, 131.58, 130.62 (d, J=1 Hz), 128.84 (q,J=31 Hz), 127.79, 125.63, 125.16, 123.46, 121.30, 117.41, 112.80 (d,J=24 Hz), 47.54 (d, J=5 Hz), 23.22 (d, J=1 Hz), 22.56 (d, J=4 Hz), 0.76.

³¹P NMR (203 MHz, C₆D₆) δ_(P) 29.0 (d, J=12 Hz), −8.5 (q, J=12 Hz). HRMS(ESI) m/z calc'd for C31H41N2NiOP2 (M-pyridine) 653.1984.

To a round bottom flask containing magnesium turnings (0.49 g, 20.3mmol) and THF (50 mL) was added a small crystal of iodine. Then,1-bromo-2,4-dimethoxybenzene (4.0 g, 18 mmol) as a solution in THF (15mL) was added slowly over 2 hours. After initiation and stirring for 2hours the solution was transferred by cannula slowly to a solution ofPBr₃ (2.94 g, 9.21 mmol) in THF (15 mL) at 0° C. The solution wasstirred overnight at room temperature, then concentrated to 20 mL totalvolume, brought into an inert atmosphere glovebox, and filtered throughCelite. Solvent was removed by vacuum to yield 5.3 g of crudebromobis(2,4-dimethoxyphenyl)phosphine which was used in subsequentreactions without further purification.

¹H NMR (500 MHz, CDCl₃) δ 7.33 (dd, J=8.5, 3.6 Hz, 1H), 6.52 (dd, J=8.5,2.3 Hz, 1H), 6.45 (dd, J=4.8, 2.3 Hz, 1H), 3.82 (s, 6H).

³¹P NMR (121 MHz, CDCl₃) δ_(P) 70.10.

To a solution of N,N,N′,N′-tetramethyl phenylphosphonic diamide (0.20 g,0.94 mmol) in THF (20 mL) was added t-BuLi (0.72 mL, 1.22 mmol, 1.7 M inpentane) at 0° C. and stirred for 30 min. A THF solution ofbis(2,4-dimethoxyphenyl)bromophosphine (0.40 g, 1.0 mmol, 6.0 mLsolution) was added to the reaction mixture and then warmed slowly toroom temperature and stirred for 30 min. The desired PPDA ligand C1a(0.15 g, 30.8% yield) was isolated as a 2:1 mixture withN,N,N′,N′-tetramethyl phenylphosphonic diamide as a white solid bysilica gel column chromatography with CH₂Cl₂/MeOH (95:5) as eluent. Thismixture was carried forward without additional purification.

¹H NMR (300 MHz, CDCl₃) δ 8.24 (m, 1H), 7.42 (m, 1H), 7.34 (m, 1H), 7.10(m, 1H), 6.49 (m, 4H), 6.39 (m, 2H), 3.81 (s, 6H), 3.68 (s, 6H), 2.55(d, J=10 Hz).

³¹P NMR (121 MHz, CDCl₃) δ_(P) 30.57 (d, J=0.9 Hz), 29.64 (s, residualphosphonic diamide starting material), −30.69 (br).

C1a (0.10 g, 0.19 mol) and(η²,η²-cyclooctadi-1,5-ene)(chloro)(methyl)palladium (0.05 g, 0.19 mmol)were weighed into a small vial and then dissolved in dichloromethane (3mL) at room temperature. The solution was stirred for 10 min. Pentanewas layered on top of the solution. After standing overnight, the motherliquor was decanted, the solids were washed with pentane, then driedunder vacuum to afford C1b (0.11 g, 84% yield) as a yellow solid. Thiscomplex was carried forward without additional purification.

¹H NMR (501 MHz, CDCl₃) δ 7.50 (m, 3H), 7.37 (m, 2H), 6.44 (br, 5H),3.82 (s, 6H), 3.55 (b, 6H), 2.57 (br, 12H), 0.42 (d, J=9.0 Hz, 3H).

³¹P NMR (203 MHz, CDCl₃) δ_(P) 33.41 (d, J=10 Hz), 21.57 (d, J=9.0 Hz).

C1b (66 mg, 0.074 mmol) and 2,6-lutidine (9 mg, 0.084 mmol) were weighedinto a small vial and then dissolved in dichloromethane (5 mL). Afterdissolution, the solution was added to a flask containing sodiumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate (50 mg, 0.074 mmol)cooled to −78° C. The mixture was slowly warmed to room temperature withvigorous stirring over 30 min. The solids were removed by filtrationthrough Celite, and the filtrate was concentrated to ca. 2 mL and thenthe solution was diluted with toluene (10 mL). After standing overnight,the precipitate was filtered and washed with pentane, then dried undervacuum to afford 30 (71 mg, 58% yield) as a pale yellow solid.

¹H NMR (501 MHz, CDCl₃) δ 7.70 (m, 8H, BAr^(F)), 7.61 (t, J=9 Hz, 1H),7.51 (m, 4H, BAr^(F)), 7.47 (m, 3H), 7.38 (m, 1H), 7.15 (m, 2H), 6.96(m, 1H), 6.58 (m, 5H), 3.85 (s, 6H), 3.56 (br, 6H), 3.05 (br, 6H), 2.52(s, 6H), 2.24 (b, 12H), −0.10 (d, J=3 Hz, 3H).

¹³C NMR (126 MHz, CDCl₃) δ 161.81 (dd, J=99.7, 49.8 Hz), 138.67, 136.38(d, J=11.4 Hz), 135.96 (dd, J=47.5, 8.0 Hz), 134.91, 132.68 (t, J=10.3Hz), 132.43, 131.27 (d, J=18.1 Hz), 130.95 (dd, J=7.4, 2.5 Hz),130.25-129.86 (m), 129.00 (qdd, J=31.4, 5.7, 2.8 Hz), 127.91, 125.75,123.58, 122.87, 121.41, 117.58, 105.44, 98.88, 55.65, 55.12 (d, J=50.5Hz), 36.16 (d, J=170.8 Hz), 26.20 (d, J=81.6 Hz), −2.62.

³¹P NMR (203 MHz, CDCl₃) δ_(P) 33.64 (d, J=18.0 Hz), 21.59 (d, J=18.0Hz). HRMS (ESI) m/z calc'd for C27H37N2O5P2Pd+ (M-Lutidine) 637.1207,found 637.1198.

To a solution of N,N,N′,N′-tetramethyl4-(N,N-dimethylaminophenyl)phosphonic diamide (0.20 g, 0.78 mmol) in THF(20 mL) was added t-BuLi (0.6 mL, 1.0 mmol, 1.7 M in pentane) at 0° C.and stirred for 30 min. A THF solution (5 mL) ofbis(2,4-dimethoxyphenyl)bromophosphine (0.33 g, 0.86 mmol) was added tothe reaction mixture and then warmed slowly to room temperature thenstirred for 30 min. The desired product C2a (0.11 g, 25.1% yield) wasisolated as a 2:1 mixture with residual N,N,N′,N′-tetramethyl4-(N,N-dimethylaminophenyl)phosphonic diamide as a yellow solid aftersilica gel column chromatography with dichloromethane/MeOH (95:5) aseluent. This mixture was carried forward without further purification.

¹H NMR (300 MHz, CDCl₃) δ 8.07 (m, 1H), 7.61 (m, 1H), 6.54 (m, 2H), 6.47(m, 2H), 6.40 (m, 3H), 3.81 (s, 6H), 3.70 (s, 6H), 2.77 (s, 6H), 2.53(br, 12H).

³¹P NMR (121 MHz, CDCl₃) δ 32.05 (d, J=1.3 Hz), 31.38 (s, residualphosphonic diamide starting material), −29.42 (br).

C2a (0.07 g, 0.125 mol) and(η₂,η²-cyclooctadi-1,5-ene)(chloro)(methyl)palladium (0.033 g, 0.13mmol) were weighed into a small vial and then dissolved indichloromethane (3 mL) at room temperature. The solution was stirred for10 min. Pentane was layered on top of the solution. After standingovernight, the mother liquor was decanted, the solids were washed withpentane, then dried under vacuum to afford C2b (0.075 g, 84% yield) as ayellow solid. This material was carried forward without furtherpurification.

¹H NMR (501 MHz, CDCl₃) δ 7.63 (br, 1H), 7.35 (m, 1H), 6.72 (m, 2H),6.56 (m, 2H), 6.44 (m, 3H), 3.82 (s, 6H), 3.68 (br, 6H), 2.79 (s, 6H),2.61 (d, J=10 Hz, 12H), 0.48 (d, J=3 Hz, 3H).

³¹P NMR (203 MHz, CDCl₃) δ 35.18 (d, J=8.2 Hz), 20.96.

C2b (49 mg, 0.056 mmol) and 2,6-lutidine (7 mg, 0.06 mmol) were weighedinto a small vial and then dissolved in dichloromethane (5 mL). Afterdissolution, the solution was added to a flask containing sodiumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate (40 mg, 0.056 mmol)cooled to −78° C. The mixture was slowly warmed to room temperature withvigorous stirring over 30 min. The solids were removed by filtrationthrough Celite, and the filtrate was concentrated to ca. 2 mL and thenthe solution was diluted with toluene (10 mL). After standing overnight,the precipitate was filtered and washed with pentane, then dried undervacuum to afford 31 (80 mg, 87% yield) as a yellow solid.

¹H NMR (501 MHz, CDCl₃) δ 7.70 (m, 8H, BAr^(F)), 7.61 (m, 1H), 7.51 (m,4H, BaR^(F)), 7.15 (m, 2H), 6.72 (m, 3H), 6.48 (br, 3H), 3.84 (s, 6H),3.64 (br, 6H), 3.06 (s, 6H), 2.81 (s, 6H), 2.26 (br, 12H), −0.08 (d,J=3.5 Hz, 1H).

¹³C NMR (126 MHz, CDCl₃) δ 161.81 (dd, J=99.7, 49.9 Hz), 151.40 (dd,J=8.4, 2.4 Hz), 138.53, 136.18 (dd, J=47.1, 9.6 Hz), 134.91, 134.72 (t,J=11.5 Hz), 129.74-128.46 (m), 127.91, 125.75, 124.35, 123.58, 122.77(d, J=3.0 Hz), 121.41, 119.24 (dd, J=12.1, 5.0 Hz), 117.58, 116.28 (d,J=18.3 Hz), 114.95 (d, J=18.3 Hz), 111.88 (d, J=16.0 Hz), 107.04 (d,J=59.7 Hz), 105.31, 98.68, 55.63, 55.31, 39.66, 36.16, 26.15, −2.76.

³¹P NMR (203 MHz, CDCl₃) δ 35.27 (d, J=16.0 Hz), 21.63 (br).

HRMS (ESI) m/z calc'd for C27H37N2O5P2Pd+ (M-Lutidine) 680.16290, found680.16282.

Example 7—Polymerization of Ethylene by (PPDA)Ni Complexes

A 450 mL stainless steel autoclave was dried in an oven at 120° C., andthen allowed to cool inside the dry box. After cooling, toluene (300 mL)and an aliquot of catalyst 27 stock solution (1.35 μmol) was added. Theautoclave was then sealed, stirred in a heated oil bath. After the innertemperature reached 95 OC, the autoclave was charged with ethylene (30bar) and stirred for 15 min. The autoclave exothermed to 117° C. Thereaction was then quenched by addition of MeOH. The mixture was filteredand washed with MeOH. The solids were dried under vacuum at 80° C.overnight to afford 19.20 g polyethylene. The molecular weight andpolydispersity were determined by size exclusion chromatography. Theextent of branching in the polymer backbone was determined by ¹H NMRspectroscopy.

T_(max) yield Activity TOF M_(w) Ð Catalyst (° C.)^(a) (g) [×10⁻⁶ g (molNi)⁻¹ h⁻¹] (×10⁻⁶ h⁻¹) (×10⁻³ g mol⁻¹)^(b) (M_(w)/M_(n))^(b) Me br^(c)26^(d) 11.4 27 0.98 170 2.6 2.2 27 117 19.2 57 2.0 21 1.7 1.5 28 10911.2 33 1.2 170 2.2 n.d.^(e) 29 100 3.1 9.3 0.33 99 1.6 n.d.^(e)^(a)Maximum temperature during polymerization due to reaction exotherm.^(b)Absolute molecular weight and polydispersity determined by GPCanalysis with triple detection. ^(c)Methyl branches per 1000 carbons asdetermined by ¹H or quantitative ¹³C NMR spectroscopy. ^(d)Conditions:26 (1.25 μmol) and C₂H₄ (30 bar) were stirred in toluene (0.2 L) at 100°C. for 20 min. ^(e)Not determined.

Example 8—Polymerization of Ethylene by a (PPDA)Ni Complexes in Presenceof Functional Additive

A 450 mL stainless steel autoclave was dried in an oven at 120° C., andthen allowed to cool inside the dry box. After cooling, toluene (300mL), an aliquot of catalyst 27 stock solution (1.35 μmol) and MEHQ (0.25g, 1500 equiv.) was added. The autoclave was then sealed, stirred in aheated oil bath. After the inner temperature reached 100° C., theautoclave was charged with ethylene (30 bar) and stirred for 15 min. Thereaction was then quenched by addition of MeOH. The mixture was filteredand washed with MeOH. The solids were dried under vacuum at 80° C.overnight to afford 10.42 g polyethylene. The molecular weight andpolydispersity were determined by size exclusion chromatography.

Yield Av TOF M_(w) Ð Additive Equiv (g) [mol (mol Ni)⁻¹ h⁻¹] k_(rel)(×10⁻³ g mol⁻¹)^(a) (M_(w)/M_(n))^(a) None — 18.6 2,000,000 1 26 1.7MEHQ 1500 18.6 2,000,000 1 23 1.5 Et₂O 1500 10.4 1,100,000 0.6 26 1.7Ethyl acetate 1500 17.9 1,900,000 1 24 1.7 H₂O 1250 11.4 1,200,000 0.626 1.7 NEt₃ 1500 0.07 7,400 0.004 — — O₂ (1 atm) 0 0 0 — — ^(a)Absolutemolecular weight and polydispersity determined by GPC analysis withtriple detection.

As provided in this Example 8, polymerization continued in the presenceof the functional additives known to disrupt and/or preclude ethylenepolymerization with prior transition metal catalysts.

Example 9—Productivity of Over Time Using Complex 27

A 450 mL stainless steel autoclave was dried in an oven at 120° C., andthen allowed to cool inside the dry box. After cooling, toluene (300 mL)and an aliquot of catalyst 27 stock solution (1.35 μmol) was added. Theautoclave was then sealed, stirred in a heated oil bath. After the innertemperature reached 100° C., the autoclave was charged with ethylene(3.5 bar) and stirred for 15 min. The reaction was then quenched byaddition of MeOH. The mixture was filtered and washed with MeOH. Thesolids were dried under vacuum at 80° C. overnight to affordpolyethylene. The molecular weight and polydispersity were determined bysize exclusion chromatography.

Productivity TOF M_(w) Ð Entry time (h) yield (g) [kg (mol Ni⁻¹)] (×10⁻³h⁻¹) (×10⁻³ g mol⁻¹)^(a) (M_(w)/M_(n))^(a) 1 0.25 0.90 670 95 15 2.0 20.5 1.4 1000 76 16 1.7 3 1 3.1 2300 83 16 1.8 4 1.5 3.9 2900 68 17 1.6 52 4.3 3200 57 120 1.8 ^(a)Absolute molecular weight and polydispersitydetermined by GPC analysis with triple detection.

Example 10—Copolymerization of Ethylene and Polar Monomer Catalyzed by a(PPDA)Ni Complex

A 25 mL stainless steel autoclave was dried in an oven at 120° C., andthen allowed to cool inside the dry box. After cooling, an aliquot ofcatalyst 27 stock solution (10 μmol) and butyl vinyl ether (1.94 mL, 15mmol) were diluted with toluene to 15 mL. The autoclave was then sealed,stirred in a heated oil bath. The autoclave was charged with ethylene(30 bar), heated to 100° C. and stirred for 12 hours. The reaction wasthen quenched by addition of MeOH. The mixture was filtered and washedwith MeOH. The solids were rinsed with chloroform to remove anypoly(butyl vinyl ether) and dried under vacuum at 80° C. overnight toafford 0.65 g polyolefin. The molecular weight and polydispersity weredetermined by size exclusion chromatography. The percent incorporationof functional monomer in the polymer backbone was determined by ¹H NMRspectroscopy.

Activity M_(w) yield [×10⁻³ g (×10⁻³ Ð Catalyst (g) (mol Ni)⁻¹ h⁻¹] gmol⁻¹)^(a) (M_(w)/M_(n))^(a) % incorp.^(b) 27 0.65 5.4 9.4 2.2 0.05^(a)Absolute molecular weight and polydispersity determined by GPCanalysis with triple detection. ^(b)Methyl branches per 1000 carbons asdetermined by quantitative ¹³C NMR spectroscopy.

Example 11—Polymerization of Ethylene by (PPDA)Ni Complexes

A 25 mL stainless steel autoclave was dried in an oven at 120° C., andthen allowed to cool inside the dry box. After cooling, toluene (10 mL)and 30 (1.25 μmol, 2.0 mg) was added. The autoclave was then sealed andstirred in a heated oil bath. After the inner temperature reached 100°C., the autoclave was then charged with ethylene (30 bar) and stirredfor 15 min. The reaction was then quenched by addition of MeOH. Themixture was filtered and washed with MeOH. The solids were dried undervacuum at 100° C. overnight to afford 0.52 g white solid. The molecularweight and polydispersity were determined by size exclusionchromatography. The extent of branching in the polymer backbone wasdetermined by ¹H-NMR spectroscopy. The same procedure was repeated for31.

Example 12—Copolymerization of Ethylene and Polar Monomer by (PPDA)NiComplexes

A 25 mL stainless steel autoclave was dried in an oven at 120° C., andthen allowed to cool inside the dry box. After cooling, toluene (12 mL)30 (10.5 μmol, 17.0 mg) and methyl acrylate (3 mL, 33.1 mmol) was added.The autoclave was then sealed and stirred in a heated oil bath. Afterthe inner temperature reached 100° C., the autoclave was then chargedwith ethylene (30 bar) and stirred for 12 hrs. The reaction was thenquenched by addition of MeOH. The mixture was filtered and washed withMeOH. The polymer was redissolved in 10 mL toluene and precipitatedagain by the addition of MeOH. The solids were dried under vacuum at100° C. overnight to afford 1.03 g white solid. The molecular weight andpolydispersity were determined by size exclusion chromatography. Thecomonomer incorporation was determined by ¹H-NMR spectroscopy. The sameprocedure was repeated for 31.

Various embodiments of the invention have been described in fulfillmentof the various objectives of the invention. It should be recognized thatthese embodiments are merely illustrative of the principles of thepresent invention. Numerous modifications and adaptations thereof willbe readily apparent to those skilled in the art without departing fromthe spirit and scope of the invention.

The invention claimed is:
 1. A phosphine-phosphonic diamide (PPDA)ligand compound of Formula (I):

wherein A is selected from the group consisting of alkylene, alkenylene,arylene and heteroarylene and wherein R¹, R², R³, R⁴, R⁵ and R⁶ areindependently selected from the group consisting of alkyl, heteroalkyl,cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyl-aryl andalkyl-heteroaryl, wherein R¹ and R² optionally form a ring structure andany combination of R³, R⁴, R⁵ and/or R⁶ optionally form a ringstructure.
 2. The PPDA ligand compound of claim 1, wherein A is selectedfrom the group consisting of arylene and heteroarylene.
 3. The PPDAligand compound of claim 1, wherein A is selected from the groupconsisting of alkylene and alkenylene.
 4. The PPDA ligand compound ofclaim 2, wherein R¹ and R² are independently selected from the groupconsisting of alkyl, cycloalkyl, heteroalkyl, aryl, and heteroaryl. 5.The PPDA ligand compound of claim 2, wherein R¹ and R² are aryl.
 6. ThePPDA ligand compound of claim 2, wherein R¹ and R² are alkyl.
 7. ThePPDA ligand compound of claim 1, wherein R³-R⁶ are alkyl.
 8. The PPDAligand compound of claim 2, wherein R³-R⁶ are alkyl.
 9. The PPDA ligandcompound of claim 1, wherein a ring structure is formed by at least twoof R³-R⁶.
 10. The PPDA ligand compound of claim 1, wherein R³-R⁶ areindependently selected from the group consisting of cycloalkyl andheterocycloalkyl.
 11. A transition metal complex of Formula (II):

wherein M is a transition metal, A is selected from the group consistingof alkyl, alkenyl, aryl and heteroaryl and wherein R¹, R², R³, R⁴, R⁵and R⁶ are independently selected from the group consisting of alkyl,heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkyl-aryland alkyl-heteroaryl, wherein R¹ and R² optionally form a ring structureand any combination of R³, R⁴, R⁵ and/or R⁶ optionally form a ringstructure and wherein R⁷ is selected from the group consisting of alkyland aryl and R⁸ is selected from the group consisting of amine,heteroaryl, monophosphine, halo and sulfoxide and wherein X⁻ is anon-coordinating counter anion.
 12. The transition metal complex ofclaim 11, wherein A is selected from the group consisting of arylene andheteroarylene.
 13. The transition metal complex of claim 11, wherein Ais selected from the group consisting of alkylene and alkenylene. 14.The transition metal complex of claim 12, wherein R¹ and R² areindependently selected from the group consisting of alkyl, cycloalkyl,heteroalkyl, aryl, and heteroaryl.
 15. The transition metal complex ofclaim 12, wherein R¹ and R² are aryl.
 16. The transition metal complexof claim 12, wherein R¹ and R² are alkyl.
 17. The transition metalcomplex of claim 11, wherein R³-R⁶ are alkyl.
 18. The transition metalcomplex of claim 12, wherein R³-R⁶ are alkyl.
 19. The transition metalcomplex of claim 11, wherein a ring structure is formed by at least twoof R³-R⁶.
 20. The transition metal complex of claim 11, wherein R³-R⁶are independently selected from the group consisting of cycloalkyl andheterocycloalkyl.
 21. The transition metal complex of claim 11, whereinM is selected from Group VIIIB of the Periodic Table.